Aging increases the risk of neurodegeneration. Strong evidence implicates aggregation-mediated proteotoxicity as the cause of neurodegeneration in numerous clinically important diseases, including Alzheimer's disease, although the etiology is unclear. Emerging genetic data suggest that the aging process is linked by signaling pathways to the fidelity of protein homeostasis, including the ability to recover or dispose of misfolded or aggregated proteins. Overall this program project strives to meet two goals: 1) to understand the organismal, cell biological and molecular bases for the pathways that protect organisms from protein aggregation, and 2) to determine how these pathways become compromised as an organism ages. The Kelly Laboratory will focus on the biochemical characterization of the pathway(s) and the underlying molecular determinants of the disaggregase activity that appears to protect against age onset proteotoxicity in C. elegans and murine models of Alzheimer's and in human cells and they will test the hypothesis that amyloidogenesis is a constitutive process. The Balch Laboratory will generate senescence cell models to probe the role of age-dependent changes in exocytic and endocytic APR and Abeta processing that appear to contribute to proteotoxicity and will employ their expertise to perturb the exocytic and endocytic pathways to understand the genesis of Abeta proteotoxicity. The Dillin Laboratory will utilize genetic, proteomic and bioinformatics approaches and animal models of Alzheimer's disease to understand how and which aging-associated signaling pathways and downstream determinants affect proteotoxicity and they will carry out Abeta aggregate structure toxicity assessments in the worm Alzheimer's model. The bioinformatics, proteomics and neurosciences and neuropathology cores are each intimately associated with two or more of these projects that are themselves highly interdependent. The results obtained from this project will not only provide insight into the relationship between aging and neurodegeneration, but should provide the information necessary to develop therapeutic strategies for age-associated neurodegenerative diseases.